Question

【题目】请认真阅读下列短文，并根据所读内容在文章后表格中的空格里填入一个最恰当的单词。注意：每个空格只填1个单词。请将答案写在答题卡上相应题号的横线上。

Potential energy is the energy, chemical or physical, stored within an object, atom or molecule（分子）. Think about a car at the top of a roller-coaster （过山车）, pausing just before it slopes into the next turn. A log resting in a fireplace just before it is about to be lit is a treasure house of potential energy. As the log burns, the connections between carbon atoms that make up the wood are being broken down, and the potential energy stored within those connections is being released as heat and light. As a comet approaches a planet or star, it slows, momentarily affected by the larger body’s gravity. The potential energy builds up and then reaches a breaking point as the comet accelerates around the larger body, and is shot out to the other side.

Sports show countless examples every day of potential energy being transformed into kinetic energy. Kinetic energy is the energy of movement. When an archer（弓箭手）draws and holds her arrow, her bow is filled with stored potential energy. When she releases the bowstring, all the potential energy is quickly transformed into kinetic energy, which is transferred to the arrow that takes flight.

The transformation of stored potential energy into kinetic energy can also be made use of to power homes, factories and entire cities. The most notable example is the Hoover Dam. The Hoover Dam is an arch-gravity dam by design. This design name is the first clue as to how exactly the dam makes use of energy. Located in the Black Canyon of the Colorado River, the Hoover Dam formed, and now holds back Lake Mead — the largest reservoir in the United States.

Gravity acts as a force upon Lake Mead. Held at bay by the Hoover Dam, the waters of Lake Mead and the Colorado River gain greater potential energy with each passing moment. The Arizona and Nevada spillways（溢洪道）are two means by which the waters of Lake Mead can escape the dam. As the lake water falls over the walls into a spillway, potential energy is instantly transformed into kinetic energy. The channels through which the water normally escapes every day are the four intake towers. These towers allow the water flow through passageways to the powerhouse and hydroelectric generators. When the water reaches the intake towers and is allowed to flow down through the passageways, all the stored potential energy created by the force of gravity acting upon the water is transformed into kinetic energy, just as when water flows over the wall into a spillway. By taking advantage of the transformed potential energy of Lake Mead, the Hoover Dam provides power to California, Nevada and Arizona.

Moments like these happen all across the physical world, whether on the molecular or universe level.

Main points	Supporting details
What is potential energy?	Potential energy is the energy existing either in the chemical or physical 【1】, which is stored in an object. When a car is sloping into the next turn from the top of a roller-coaster, it is building up potential energy. When a log is burning, the connections between carbon atoms are being broken down, 【2】 potential energy as light and heat. When a comet approaches a planet or star, the potential energy 【3】 to a breaking point and then the comet is shot out to the other side.
How is potential energy transformed into kinetic energy?	Potential energy can be transformed into kinetic energy, which is the energy【4】 by movement. When the bowstring is released by an archer, the potential energy stored in the full bow is quickly transferred to the arrow, thus transformed into kinetic energy which sets the arrow 【5】 far away. Hoover Dam is the most notable example of energy transformation. Hoover Dam is 【6】 in the Black Canyon of the Colorado River, holding back Lake Mead. The waters of Lake Mead escape the Dam, falling over the walls into Arizona and Nevada spillways, leading to the 【7】 transformation from potential energy into kinetic energy. The 【8】 of potential energy is from the force of gravity acting upon the water
What 【9】 is the energy transformation made of?	Homes, factories and cities are efficiently 【10】 thanks to the powerhouses and hydroelectric generators taking advantage of the transformed potential energy.

Answer 1

【答案】

【1】form/state

【2】releasing

【3】accumulates

【4】produced / generated / created

【5】flying

【6】located/situated

【7】instant

【8】creation / formation

【9】use

【10】powered

【解析】

这是一篇说明文。势能是储存在物体、原子或分子中的化学或物理能量。这样的时刻在整个物质世界都有发生，无论是在分子层面还是在宇宙层面。

【1】

考查名词。根据第一段第一句Potential energy is the energy, chemical or physical, stored within an object, atom or molecule（分子）.“势能是储存在物体、原子或分子中的化学或物理能量。”可知，势能是以化学或物理形式存在于物体中的能量。故填form/state。

【2】

考查现在分词作伴随状语。根据第一段中As the log burns, the connections between carbon atoms that make up the wood are being broken down, and the potential energy stored within those connections is being released as heat and light.“当木头燃烧时，构成木头的碳原子之间的连接被分解，在这些连接中储存的势能被释放为热量和光。”可知，当原木燃烧时，碳原子之间的连接被打破，释放出以光和热形式存在的势能。逻辑主语 log与release之间为主动关系，所以用现在分词作状语。故填releasing。

【3】

考查动词。根据第一段最后一句The potential energy builds up and then reaches a breaking point as the comet accelerates around the larger body, and is shot out to the other side.“当彗星绕着更大的星体加速时，它的势能逐渐增加，并达到一个断裂点，然后被抛向另一边。”可知，当一颗彗星接近一颗行星或恒星时，其势能会累积到一个临界点，然后彗星就会被发射到另一边。故填accumulates。

【4】

考查过去分词作后置定语。根据第二段中Sports show countless examples every day of potential energy being transformed into kinetic energy. Kinetic energy is the energy of movement.“体育表演每天都有无数的势能转化为动能的例子。动能是运动的能量。”可知，势能可以转化为动能，动能是运动产生的能量。名词energy与动词produce / generate / create之间为被动关系，所以用过去分词作后置定语。故填produced / generated / created。

【5】

考查现在分词作宾语补足语。根据第二段中When an archer（弓箭手）draws and holds her arrow, her bow is filled with stored potential energy.“当弓箭手拉起并握住她的箭时，她的弓充满了储存的势能。”可知，当弓箭手释放弓弦时，储存在满弓上的势能迅速转移到箭上，转化为动能，使箭飞得很远。名词 arrow与动词fly之间为主动关系，所以用现在分词作宾语补足语。故填flying。

【6】

考查固定搭配。根据第三段最后一句Located in the Black Canyon of the Colorado River, the Hoover Dam formed, and now holds back Lake Mead — the largest reservoir in the United States.“胡佛水坝位于科罗拉多河的黑峡谷，现在它挡住了美国最大的水库米德湖。”可知，胡佛水坝位于科罗拉多河的黑峡谷，挡住了米德湖。短语be located/situated in坐落于。故填located/situated。

【7】

考查形容词。根据第四段中As the lake water falls over the walls into a spillway, potential energy is instantly transformed into kinetic energy. “当湖水越过堤坝进入泄洪道时，势能立即转化为动能。”可知，米德湖的水从大坝流出，越过堤坝进入亚利桑那州和内华达州的泄洪道，导致了从势能到动能的瞬间转换。故填instant。

【8】

考查名词。根据第四段中When the water reaches the intake towers and is allowed to flow down through the passageways, all the stored potential energy created by the force of gravity acting upon the water is transformed into kinetic energy, just as when water flows over the wall into a spillway.“当水到达进水塔，并允许通过通道向下流动时，所有由重力作用在水上产生的储存的势能都转化为动能，就像水流过墙变成泄洪道一样。”可知，势能的产生是由于作用在水上的重力。故填creation / formation。

【9】

考查固定词组。根据倒数第二段中By taking advantage of the transformed potential energy of Lake Mead, the Hoover Dam provides power to California, Nevada and Arizona.“通过利用米德湖转化的势能，胡佛大坝为加利福尼亚州、内华达州和亚利桑那州提供电力。”可知，能量转换有什么用?固定词组：take advantage of利用；make use of利用。故填use。

【10】

考查一般现在时态的被动语态。根据倒数第二段中By taking advantage of the transformed potential energy of Lake Mead, the Hoover Dam provides power to California, Nevada and Arizona.“通过利用米德湖转化的势能，胡佛大坝为加利福尼亚州、内华达州和亚利桑那州提供电力。”可知，由于发电厂和水力发电机利用了转化后的潜在能量，家庭、工厂和城市能够有效地获得电力。故填powered。